No they wouldn't ...you would still have to guard the Steph & Klays of the game.
The Warriors made 43 more threes than the Grizz in their series, 7 per game difference.
The year before that the Thunder made 25 more threes, game 7 the Thunder were 11-19 from three, the Grizz were 5-17.
The year before that the Spurs used the threat of the three to dismantle them.
The year before that the Clippers beat them in 7, having made 19 more threes and in game 7 the Grizz didn't make a single three.
The year before that the Thunder beat them in 7 and made 19 more threes in the series.
We're talking about a team that won 50+ games while being one of the worst three point shooting teams in the league, and you can point to the lack of 3 point shooting as the reason they've lost several series. Without the three point shot they would have won a few titles, they were built with the old rules in mind and it showed when they kept coming up short vs teams that could shoot.
This years Jazz team would be a serious threat to win the title without a 3 line, because Gobert's defense gets that much better when he doesn't need to respect dudes taking 23 foot 2 pointers.